Treating hydrocarbons



Sept. 29, 1931.

I V. N. JENKINS ET AL TREATING HYDROOARBONSI Filed June 14 raxr/omrwa val/MAI Patented Sept. 29, 1931 UNITED "STATES PATENT; oFFlca VANCE N. JENKINS AND CHARLES I. WILSON, JR,

OF PORT ARTHUR, TEXAS, ASSIGNOBB BY KESNE ASSIGNMENTS, TO THE TEXAS COMPANY, OF NEW YORK, N. Y A 003- IORATION OI DELAWARE Application filed June 14,

This invention relates to the treatment of hydrocarbons, such aspetroleum and other chlorid as a treating'agent for hydrocarbon oils mainly for the purpose of increasing the yield of the lower boiling products obtainable from such oils. However, the difiiculties in this general method of treatment have prevented any extensive use of the process. For instance, one of the chief difliculties in distilling oil. in the presence of aluminum chlorid, as it has been practiced, has been that when the oil was heated to temperatures above the volatilizing temperature of aluminum chlorid, evolution of aluminum chlorid vapors occurred with the result that the vapor lines of the distilling equipment would frequently be choked up by chlorid condensed therein. It has been sought to employ some form of preliminary cooler to separate out from the vapors at least a portion of the evolved aluminum chlorid but it has been practically impossible to separate out all of the aluminum chlorid without thereby condensing with it appreciable quantities of the gasoline product desired. Moreover, the sublimation of the chlorid in this manner has served to remove from the more heated portion of the still quantities of the chlorid which thus, decreased the yield of light hydrocarbons. The presence of the sublimed chlorid in the vapor portions of the apparatus has made it impracticable to provlde the distilling apparatus with any efficient fractionating means and it has been necessary to redistill the condensate obtained from the apparatus in order to obtain the fractionated product desired.

The disadvantages incident to the evolu-' tion of aluminum chlorid vapors have been especially obstructive in the attempts'made to carry on a continuous distillation with aluminum chlorid, since whenever additional quantities of the chlorid were addedto the, heated contents of the still there would be copious evolution of aluminum TREATING nxmzocnnnons 1824. Serial No. 719,970.

chlorid vapors, and in an effort to check to some extent this vaporization the'practice has sometimes been followed of slackening the fires under the still prior to the adding of each fresh quantity of chlorid, but this practice was only an expensive makeshift which increased the fuel required and which did not prevent the ultimate evolution of chlorid vapors from the still. 1'

It has been the practice, and in fact, has been necessary, to fire aluminum chlorid stills comparatively. slowly in order to check somewhat the vaporization of the chlorid and to obtain a long period of contact between the oil and chlorid in the effort to secure adequate yields. The result has been that the fuel expense in distilling oil with aluminum chlorid has commercial operation of the process practically impossible. These and other disadvantages, some of which are discussed hereinafter, of the existing methods of employing aluminum chlorid in the treatment of made a successful hydrocarbon oils have been successfully overcome by the practice of our invention.

We have found that if the treatment of hydrocarbons be carried on with certain metallic halid material, such as aluminum chlorid material, in the presence of a hydrogen halid, as hydrogen chlorid, there is no material evolution of vapors of the metallic halid'regardless of the temperature to which the hydrocarbons may be heated.

We have also found that if the oil be treated with a reactive compound formed by contacting hydrocarbons and a metallic halid, such as aluminum chlorid, in the presence of a hydrogen halid that no material amount of aluminum chlorid is vaporized out of the.- heated hydrocarbons. Wehave, moreover, found that a very rapid reaction occurs between the hydrocarbons and the metallic halid or compound thereof either when extraneous hydrogen halid is admitted to the heated mixture of metallic halid and hydrocarbons or when the hydrocarbons are treated with a reactive compound of metallichalid and oil prepared in the presence of hydrogen halid.

Broadly and generally our invention contemplates the treatment of hydrocarbons, such as petroleum and itsproducts and other hydrocarbon oils, with anhydrous metallic halid or a compound thereof with hydrocarbons, in the presence of, or: under conditions favorable to the roduction of hydrogen halid. The anhy rous halids of alummum are articularly well adapted for the practice of the invention, the oil being treated, or the hydrocarbon halid compound being formed, by contacting, for example, anhydrous aluminum chlorid and hydrocarbons in the presence of a hydrogen halid, such as hydrogen chlorid. The treatment in the presence of the hydrogen chlorid may be carried on in various ways. For example, extraneous hydrogen chlorid may be brought into contact with the hydrocarbons apd aluminum chlorid or compounds there- 0 It' is not necessary that dry hydrogen chlorid be used, since it is quite feasible to use the solution, that is hydrochloric acid. It has been thought that the treatment of hydrocarbons with aluminum chlorid-treating materials could not take place if moisture or water were present and for this reason great care has been exercised in prior methods in drying or dehydrating the oil before treating it with aluminum chlorid. In our process such practice is not necessary because the presence of water or moisture results in hydrolysis of a portion of the aluminum chlorid witha resultant produc tion of hydrogen chlorid which is a beneficial agent in our method. Thus in treating petroleum oils, for instance, it is feasible to employ plant run distillates, or other oils which frequently contain more or less moisture, and charge these directly to the treating apparatus without the necessity of having to first dehydrate the.cil. It may be stated, however, that it is desirable not to have an excessive quantity of moisture or water 1present'in the oil being treated because t e presence of moisture, while it does result in the production of hydrogen chlorid, also produces decomposition of the aluminum chlorid. We therefore prefer to employ substantially dry oils and to insure the presence of hydrogen chloridby the use of dry hydrogen chlorid, although it is quite feasible to charge continuously or intermittently into the still oils containing small proportions of moisture, since the presence of the moisture insures that there will be no appreciable evolution of aluminum chlorid vapors.

It is not necessary that. the hydrogen chlorid be added continuously and a good method of operation is to add the hydrogen chlorid gas or hydrochloric acid or water from time to time as may be desired. If the distillation or heating of the oil in the presence of uncombined or free aluminum chlorid be carried on for a time without an adequate supply of hydrogen chlorid and with a consequent sublimation of aluminum chlorid vapors such deposits of condensed chlorid as may occur may be removed by admitting to the treatin apparatus a quantity of hydrogen chlori The action of aluminum chlorid, or the compounds or mixtures thereof with which it has been sought to treat hydrocarbons, has fre uently been designated as a catalytic one an the aluminum chlorid, or compositions thereof which have been used, have been regarded as catalysts. In our process the action of the aluminum chlorid, and the action of the compounds prepared in accordance with our invention, is not thought to be a catalytic-one. In the practice of the invention a compound of aluminum chlorid and hydrocarbons is formed which when heated in contact with other hydrocarbon material results in the conversion of higher boiling hydrocarbons into lower boiling ones and the reaction according to our present knowledge and belief is a straight chemical reaction, or rather a series of chemical reactions, in which lighter or lower boiling products are formed. The quantity of lower boiling point products formed appears to be a direct function of the amount of the aluminum chlorid present and'on'ge the reaction has gone to completion it is impossible to produce any more lower boiling products by prolonged heating or other means. The

quantity of aluminum chlorid used is therefore largely determined by economic considerations. 4

Our invention contemplates a non-volatile compound of aluminum chlorid or other metallic halid and hydrocarbons which is adapted to act as a reactive agent for treating hydrocarbon oils. In the prior art the mixtures of oil and aluminum chlorid that it has been sought to employ have been of such character that when the oil was heated in the presence of the mixture, aluminum.

chlorid vapors would be vaporized therefrom. We have found that by contacting oil or other hydrocarbons with aluminum chlorid in the presence of hydrogen chlorid, either at normal temperatures or under the influence of heat, that a compound of aluminum chlorid and hydrocarbons is formed which is non-volatile regardless of the temperature to which it may be subjected. When this compound is admitted to a still or retort and other hydrocarbon material heated in its presence there results a conversion of higher boiling into lower boiling hydrocarbons without the evolution of aluminum chlorid vapors. The great technical advantage of the use of such a compound is apparent, since the still or retort may be held at any temperature desired and suitable fractionating equipment may be provided in connection with the distilling apparatus so as to obtain a suitably fractionated condensate directly from the conversion apparatus. It is of course unnecessary toprepare the compound outside of the still or treating vessel since the aluminum chlorid of suspended matters and being freely mobile and capable of being readily handled by pumps. The characteristics vary somewhat with the temperature at which the compound is made. Thus it is less viscous when made at lower temperatures and in general the viscosity tends to increase as the temperature at which it is made increases. Its color when viewed by transmitted light varies from a pale yellow when made at lower temperatures to a dark red when made at the higher temperatures, the darker colors being black by reflected light. Y

The reactive agent may be prepared from petroleum hydrocarbons at practically any temperature. However, when the compound is formed prior to its admission to the treating or distilling vessel it is generally desirable to employ a temperature at which the reaction will take place fairly rapidly Without having a production of material proportions of the lighter or lower boiling hydrocarbons and ordinarily we prefer to employ a temperature in. excess of 100 F. and preferably use a temperature around 200 F., the oil and dry chlorid being contacted or mixed together at such temperatures in the presence of extraneous hydrogen chlorid or moisture. If desired, however, the treating agent may be made at higher temperatures simultaneously with the production of lower boiling hydrocarbons. The oil or other hydrocarbon material may be vaporized and the vapors brought into contact with the solid aluminum chlorid in the presence of hydrogen chlorid to form the reactive agent and lower boiling hydrocarbons.-'

By way of example it may be stated that in a number of cases in which the reactive agent was made by contacting kerosene and gas oil fractions of petroleum with alumi num chlorid in the presence of hydrogen chlorid that the resultant compound had specific gravities varying from about 1.24

be added directly to the" oil in the still to 1.27. 'On analyzing the product it'was found that about 60%. by weight was aluminum chlorid, approximately 12% being aluminum and 50% chlorin, the remainder "consisting of hydrocarbons. It is to be understood that the specific characteristics thus given have been stated for illustrative purposes intended to show certain products that may beobtained by the practice of the invention and it is not intended to thereby limit the scope of the invention to the specific products described.

Our investigations indicate that the hydrogen halid does not enter-into the composition of the final product. It appears to act as a catalyst which promotes the chemical combination of the metallic halid with hydrocarbons.

One of the chief advantages of our invention is that it enables the complete utilizationof the aluminum chlorid material employed by preventing, during the operation of the process, the vaporzation of the chlorid as such. The chlorid or the compounds thereof with hydrocarbons may be held in the reaction zone, so that substantially all of the aluminum chlorid content may be utilized in the conversion or treatment of the hydrocarbon material. The presence of an adequate supply of the hydrogen chlorid insures that the aluminum-chlorid material will be fully utilized and if the process be properly carried'out there should be little or no aluminum chlorid in the residual product withdrawn from the treating appathe invention.

' Figure 2 is a diagrammatic view in sectional elevation of an apparatus adapted es pecially for the preparation of the reactive agent. I

In the apparatus illustrated in Figure 1. a still 10 is provided, being suitably supported in a furnace 11 or otherwise arranged to be supplied with heat. The still is equipped with a charging line 12 for introducing the hydrocarbon oil to be treated and with an outlet line 13 for withdrawing the spent reactive material or other residual matters that it may be' desired to remove from the still. The conduit 13 is preferably protected from the atmosphere by insulation, or heating means may be provided, in'

When it is intended to charge the-dry aluminum chlorid into the still a hopper 14 may be provided but if it is desired to introduce the chlorid in the form of a liquid reactive compound a conduit connected to a suitable supply of such reactive agent is provided. A pipe 15 is provided for introducing the hydrogen chlorid or other extraneous agent which it may be desired to employ. The pipe 15 preferably terminates beneath the normal liquid level in the still and may well communicate with a perforated spray or discharge pipe 16 positioned near the bottom of the still. When the treatment is carried on by admitting the solid chlorid to the still it is sometimes desirable to provide, in addition to the pipe 15 entering the still, .one or I more connections communicating with the vapor lines or fractionating apparatus of the still so that hydrogen chlorid may be admitted to these portions of the apparatus.

In prior methods of treating oils with aluminum chlorid it has been necessary to provide some sort of agitating, stirring, or

scraping mechanism in order, not only to obtain contact between the aluminum chlorid employed and the oil, but to prevent, or at least hinder', the formation of injurious coke deposits on the heated surfaces of the still. i

In the practice of our invention such agitating, stirring or scraping mechanism is unnecessary. The hydrogen chlorid present in our method of operation appears to act as a catalyst which insures the formation of the liquid compound or reactive agent, the reaction of which with hydrocarbons brings about the conversion of higher boiling into lower boiling products, and even though solid aluminum chlorid may/be admitted to thestill the hydrogen chlorid insures that this chlorid will be chemically combined or absorbed in the oil in such a manner as to form a homogeneous liquid product containing little or no suspended aluminum chlorid or other material which would necessitate the use of scraping or stirring mechanism. The final spent product which is removed from the still is also of a homogeneous nature and when in a heated condition is liquescent and freely mobile. If desired, however, suitable agitating, stirring or scraping means may be provided in the still, since while such apparatus is not regarded as necessary in the practice of our invention our method does not necessarily preclude the use of such mechanism.

The still is provided with a vapor line 17 which preferably extends to a fractionating device 18 which may comprise one or more fractionating towers or chambers, such for example as packed towers, bubble towers, and the like, whichareadapted to fractionate the vapors. A backtrap or reflux line 19 may be provided to return to the still the heavier or higher boiling point fractions which are collected as a condensate in the fractionating apparatus. It is generally desirable to have the pipe 19 enter the still at a point below the normal liquid level thereof but at a point somewhat above the bottom of the still where the reactive compound and residual products of the reaction tend to accumulate. A vapor line 20 serves to remove the vapors from the fractionating apparatus and conduct them to a condenser 21, a' receiving vessel 22 being provided in which to collect the condensate formed in the condenser. The apparatus may be equipped with such control valves as may be deemed necessary and may be arranged to operate under a superatmospheric pressure or under a diminished pressure or vacuum.

In using the apparatus thus described the hydrocarbon material that it is intended to treat, such for exampleas kerosene, gas oil 'and the like, is admitted to the still through the charging line 12 and, if it is desired to admit the solid chlorid, this material is charged into the still through the hopper 14. The hydrogen chlorid is introduced through the pipe 15 and distributed into the contents of the still by means of the perforated pipe 16. Heat is applied and the oil is "raised to distilling temperatures. Either the batch or the continuous method of operation may be employed. The introduction of the hydrogen chlorid into the still contents insures that there will be no material evolution of aluminum chlorid vapors therefrom and facilitates a smooth and even operation of the still. In the continuous method of operation additional quantities of oil and aluminum chlorid may be admitted as desired and residual products either continuously or intermittently withdrawn through the outlet 13 so as to maintain a substantially constant liquid level of the oil undergoing conversion.

As pointed out previously it is unnecessary to introduce the hydrogen chlorid continuously during the operation, although this may be done if desired. It is generally sufficient, however, to admit the hydrogen chlorid for comparatively short, intermittent periods during the operation. If, instead of introducing the solid aluminum chlorid to the still it is desired to introduce the reactive compound formed in accordance with our invention, this material may be admitted either continuously or intermittently, as desired, through a suitable charging line and it is generally unnecessary in this case to add extraneous HCl.

The condensable product desired, such as gasoline, is collected as a condensate in the receiver 22. It will be observed that since this product has been suitably fractionated in the apparatus 18 it is unnecessary to redistill the product to obtain the particular fractionated product desired.

In starting a run a very successful method of operation is to first introduce into the chlorid is admixed with the oil in the pres-- Laramie I still a desired quantitylofoil, then introducethe solid alummumc orid, then start bubbling hydrogen chlorid through the contents and start the fires of the furnace. In this method of operation the imtlal charge of reactive compound is formed at a compara tively low temperature while the s t1ll 1s bein brought up to operating conditions.

W on it is desired to merely purify the hydrocarbons so as to obtain an lmprovement in color and to stabilize the character of the hydrocarbons without thereby forming any material portion of lower bOlllIlg po1nt products the reactive compound prepared in accordance with our'invention is contacted or agitated w th the hydrocarbon material to be treated, or solid aluminum ence of extraneous hydrogen chlorid. The treatment is carried on under moderate heating preferably not over 150 F. and in fact .it is possible in our process totreat the oil at normal temperatures without the application of any heat whatever. It is thus com- Referring now to the apparatus illustrat-- ed in Figure 2 it will be seen that a contact or reaction chamber 25 is provided inwhich to prepare the reactive compound or agent. The, chamber is provided with a hopper 26 for introducing the aluminum chlorid and with a pipe '27 for admitting the oil or other hydrocarbon material. The vessel 25 is preferably provided with a perforated plate 28 or other means for preventing solid particles of aluminum chlorid from passing into the bottom of the chamber. The vessel is preferably insulated and provided with a steam coil 29 or other suitable heating means. The hydrogen chlorid is admitted by means of a pipe 30 which-preferably communicates with the lower part of the chamber 25 below the plate 28. A blower 31 may be provided for forcing the gas'into the chamber. ing an inlet pipe 32 which has valved branch connections 33 and 34, the formerof which extends to a suitable source of hydrogen chlorid and the latter ofwhich communicates with the upper portion of the chamber 25. Since, as hereinbefore stated, the

hydrogen chlorid does not itself enter into the composition of the reactive agent formed it may be reused and since the hydrogen chlorid tends to collect in the upper portion of the chamber 25-, the gas may be The blower is shown as hav-- drawn oil through the pipe 34 and thus reused.

As previously stated, various temperatures may be employed in the preparation of the reactive compound. .We prefer, however, to use a temperature around 200 F. since at this temperature the compound can be made rapidly with a minimum production of lighter or lower boiling point products. The preparation of the compound or treating agent in the vessel 25 may, however, by

accompanied with a greater or less conversion of higher boiling hydrocarbons into lower boiling ones so that the gaseous prod ucts collecting in the upper portion of the chamber comprise condensable and noncondensable hydrocarbons and hydrogen chlorid. In this case it is well to provide a condenser in connection with the outlet line 34 so that the condensable hydrocarbons may be separated out and thus only the noncondensable hydrocarbons and the hydrogen chlorid cycled through the system.

An important application of our invention resides in the treatment of hydrocarbons for the production of'condensation or polymerization products. This feature of the invention relates especially to the treatment of unsaturated hydrocarbons, or oils having a relativly high content of unsaturated bodies, for the production of products of increased viscositi'es. In accordance with the invention the unsaturated hydrocarbon materials are contacted with aluminum chlorid or other metallic halid in the presence of hydrogen halid, or are treated with a reactive agent. formed by the admixing of the metallic halid and hydrocarbons in the presence of hydrogen halid. The treatment can be carried on at relatively low temperatures so that, if desired, the formation of lower boiling products can be practically eliminated, and in fact the treatment may even be carried on in the. absence of any heating whatever.

' In describing this invention in detail particular reference has been made to the use of aluminum chlorid but it is to be understood that variousmetallic halids may be employed, the aluminum halids being pre-- ferred.- Any suitable hydrogen halid, such as hydrogen chlorid and hydrogen bromid,

may be nsed in the practice of the invention. In treating the hydrocarbons with a 'venaluminum halid, or other metallic hali the corresponding hydrogen halid may be employed or, if desired, any of the other hydrogen halids may be used. Thus, for example, in using aluminum chlorid either hydro en chlori or hydrogen bromid or other ydrogen halid may be employed and with aluminum bromid hydrogen bromid or' hydrogen chlorid or other hydrogen halid ma be employed.

bviously many modifications and variaride and hydrocarbons, subjectin 'to be converted to the action of sai treating tions of the-invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof and therefore, only such limitations should be imposed as are indicated in the appended claims.

What we claim is:

1. The process of treating hydrocarbon oils to convert higher boiling hydrocarbons into lower boiling hydrocarbons which comprises treating a petroleum fraction with aluminum chloride and hydrogen chloride below the conversion temperature of the oil to form a liquid treating agent consisting of aluminum chloride and hydrocarbons, mixing said treating agent with the oil to be converted, heating the mixture to a conversion temperature, introducing hydrogen chloride gasinto said'mixture to produce an even evolution of vapors and to maintain the treating agent in an active condition, separating-the vapors of low boilin products and withdrawing residual liquid before substantial accumulation oat coke has occurred.

2. The process of treating hydrocarbon oils to convert higher boiling hydrocarbons into lower boiling hydrocarbons which comprises subjecting a hydrocarbon oil to the action of aluminum chloride and hydrogen chloride below the conversion temperature of the oil to form a liquid treating agent comprising a compound of aluminum chlothe oil agent at conversion temperature of the oil while in the presence of extraneous hydrogen chloride, fractionating the resultant vapors of lower boiling hydrocarbons to form a vapor fraction comprising gasoline and a reflux condensate, and returning said reflux condensate to the oil undergoing converslon.

In witness whereof we have hereunto set our hands this 22nd day of May, 1924-.

VANCE N. JENKINS. CHARLES P. WILSON, JR. 

